BlendMode颜色混合模式枚举值

来源：互联网发布：吕思勉知乎编辑：程序博客网时间：2024/06/05 15:53

BlendMode参数值及表现形式

blendMode作用

在对图片进行手动处理的时候，可能用到图层混合，如改变图片的颜色。常常获取CGContext,然后设置其blendMode参数。

为了形象理解BlendMode值的变化，我使用了一张主图标和辅图标（支付宝图标）作为测试，测试颜色为红色，注释中有序号的可以对应其变换结果

BlendModel参数值结束

如下（转）：

    switch (blendMode) {          case kCGBlendModeNormal: {              strMsg = @"kCGBlendModeNormal: 正常；也是默认的模式。前景图会覆盖背景图";              break;          }          case kCGBlendModeMultiply: {              strMsg = @"kCGBlendModeMultiply: 正片叠底；混合了前景和背景的颜色，最终颜色比原先的都暗";              break;          }          case kCGBlendModeScreen: {              strMsg = @"kCGBlendModeScreen: 滤色；把前景和背景图的颜色先反过来，然后混合";              break;          }          case kCGBlendModeOverlay: {              strMsg = @"kCGBlendModeOverlay: 覆盖；能保留灰度信息，结合kCGBlendModeSaturation能保留透明度信息，在imageWithBlendMode方法中两次执行drawInRect方法实现我们基本需求";              break;          }          case kCGBlendModeDarken: {              strMsg = @"kCGBlendModeDarken: 变暗";   //将线条色变为黑色，背景色设置为目的色            break;          }          case kCGBlendModeLighten: {              strMsg = @"kCGBlendModeLighten: 变亮";              break;          }          case kCGBlendModeColorDodge: {              strMsg = @"kCGBlendModeColorDodge: 颜色变淡";              break;          }          case kCGBlendModeColorBurn: {              strMsg = @"kCGBlendModeColorBurn: 颜色加深";  //线条颜色（原本）加深，背景色设置为目的色            break;          }          case kCGBlendModeSoftLight: {              strMsg = @"kCGBlendModeSoftLight: 柔光";              break;          }          case kCGBlendModeHardLight: {              strMsg = @"kCGBlendModeHardLight: 强光";  //全为目的色            break;          }          case kCGBlendModeDifference: {              strMsg = @"kCGBlendModeDifference: 插值";              break;          }          case kCGBlendModeExclusion: {              strMsg = @"kCGBlendModeExclusion: 排除";              break;          }          case kCGBlendModeHue: {              strMsg = @"kCGBlendModeHue: 色调";              break;          }          case kCGBlendModeSaturation: {              strMsg = @"kCGBlendModeSaturation: 饱和度";              break;          }          case kCGBlendModeColor: {              strMsg = @"kCGBlendModeColor: 颜色";   //感觉将图片线条色设置为白色，背景色设置为目的色，之后再再图片上加一个有透明度的目的色            break;          }          case kCGBlendModeLuminosity: {              strMsg = @"kCGBlendModeLuminosity: 亮度";              break;          }              //Apple额外定义的枚举              //R: premultiplied result, 表示混合结果              //S: Source, 表示源颜色(Sa对应透明度值: 0.0-1.0)              //D: destination colors with alpha, 表示带透明度的目标颜色(Da对应透明度值: 0.0-1.0)          case kCGBlendModeClear: {              strMsg = @"kCGBlendModeClear: R = 0"; //1.清空（如果图标背景色为白色则为全白）             break;          }          case kCGBlendModeCopy: {              strMsg = @"kCGBlendModeCopy: R = S";  //2全色覆盖整个图片            break;          }          case kCGBlendModeSourceIn: {              strMsg = @"kCGBlendModeSourceIn: R = S*Da";  //3.线条变色            break;          }          case kCGBlendModeSourceOut: {              strMsg = @"kCGBlendModeSourceOut: R = S*(1 - Da)";  //4.背景变为目的色,线条自动变为白色（比如图标线条原为蓝色，会自动变为白色）            break;          }          case kCGBlendModeSourceAtop: {              strMsg = @"kCGBlendModeSourceAtop: R = S*Da + D*(1 - Sa)";   //5.线条变色，目前感觉和SourceIn效果一致            break;          }          case kCGBlendModeDestinationOver: {              strMsg = @"kCGBlendModeDestinationOver: R = S*(1 - Da) + D";  //6.背景色变为目的色，线条色不变            break;          }          case kCGBlendModeDestinationIn: {              strMsg = @"kCGBlendModeDestinationIn: R = D*Sa；能保留透明度信息";  //7.只看到线条色（本色），无其他颜色            break;          }

        case kCGBlendModeDestinationOut: {              strMsg = @"kCGBlendModeDestinationOut: R = D*(1 - Sa)";     //8.空白什么都没哟            break;          }          case kCGBlendModeDestinationAtop: {              strMsg = @"kCGBlendModeDestinationAtop: R = S*(1 - Da) + D*Sa";  //9.会把整个矩形的背景填充目的色（如图9系列）原色保留            break;          }          case kCGBlendModeXOR: {              strMsg = @"kCGBlendModeXOR: R = S*(1 - Da) + D*(1 - Sa)";  //10.线条变白，背景色变为目的色            break;          }          case kCGBlendModePlusDarker: {              strMsg = @"kCGBlendModePlusDarker: R = MAX(0, (1 - D) + (1 - S))";  //11.线条变为黑色， 背景色变为目的色            break;          }          case kCGBlendModePlusLighter: {              strMsg = @"kCGBlendModePlusLighter: R = MIN(1, S + D)（最后一种混合模式）";  //12.线条变为白色（混合色：如color为红色，就是偏粉色的白，有一定透明度的感觉）            break;          }          default: {              break;          }

以上中文解释(含//）是在如下代码段情况下发生的，不同代码段可能表示形式不一。

测试图标依赖下面代码，实际使用要考虑实际效果

改变图标代码参考:

func changeColor(_ color:UIColor, blendMode:CGBlendMode) -> UIImage {        //方式一（可以）        UIGraphicsBeginImageContextWithOptions(self.size, false, UIScreen.main.scale)        let context = UIGraphicsGetCurrentContext()        color.setFill()        //移动图片        context!.translateBy(x: 0, y: self.size.height)        context!.scaleBy(x: 1.0, y: -1.0)                let rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)        context!.draw(self.cgImage!, in: rect)        //模式配置        context!.setBlendMode(blendMode)        context!.addRect(rect)        context!.drawPath(using: CGPathDrawingMode.fill)        //创建获取图片        let coloredImage = UIGraphicsGetImageFromCurrentImageContext()        UIGraphicsEndImageContext()                return coloredImage!}